Fluid apparatus



FLUID APPARATUS Filed Oct. 2 1947 INVEN a C gaazd JJ TORS. 22

Patented Jan. 24, 1950 FLUID APPARATUS Earl Cannon, Downers Grove, and Edward J.

Lukes, Brookfield,

New Jersey Ill Steel Foundries, Chic assignors to American ago, 11]., a corporation 01' Application October 2, 1947, Serial No. 777,548

14 Claims.

This invention relates to hydraulic systems and more particularly to a novel system for supplying hydraulic fluid at a predetermined adjustable pressure as, for example, to a vessel for testing the same. I

It has been found that in pressure vessel testing apparatus utilizing an hydraulic medium, such as oil, a wide range of selectivity in the pressure is frequently desirable, necessitating the use of a multiplicity of relief Valves adapted to be selectively connected to the pressure line for regulating the hydraulic pressure therein. Furthermore, in such an apparatus the pressure must be maintained by a source, such as a pump, against the relief valve resulting in excessive wearing thereof and in excessive power consumption by the pump.

An object of the present invention is to design a novel system, such as above-described, wherein the desired pressure is maintained by a pneumatic intensifier device thereby eliminating the necessity of holding the pressure against a relief valve.

Another object of the invention is to afford adjustability of th pressure in the system by providing in series a plurality of air intensifier devices, one or more of which may be actuated to adjustably vary the pressure of the hydraulic fluid supplied by the system.

Still another object of the invention is to provide means for automatically recharging the system when the volume of hydraulic fluid reaches a predetermined minimum value.

The foregoing and other objects and advantages of the invention will become apparent from a consideration of the following specification and the accompanying drawings, wherein the single figure illustrated is a flow diagram of the hydraulic system, portions O f the apparatus being shown in central vertical cross section, and a wiring diagram of the electrical actuating system associated with the hydraulic system,

Describing the invention in detail and referring to the drawing which illustrates the invention embodied in a pressure vessel testing apparatus. The system includes a supply line 2 connected to the vessel 4 to be tested. The line 2 is provided with a pressure gauge 6 and conventional stop cocks 8.

The line 2 is connected through a check valve ill to an hydraulic cylinder l2 containing a ram i4 adapted to exert a predetermined adjustable pressure against the fluid in the cylinder 12 and the line 2. The ram I4 is actuated by one or both of a pair of gas pressure intensifier devices;

generally designated I5 and Hi. The device l5 comprises a piston l8 carrying a rod 20, one end of which is engageable with the ram M, the opposite end of the rod beingengageable with a rod 22 connected to a piston 24 reciprocal within a cylinder 26 of the device It.

Compressed gas, such as air, is conveyed to the devices l5 and I6 by a line 28 having a branch 30 connected to the cylinder I! and a branch 32 connected to the cylinder 26 through a selector valve 34 adapted to connect the cylinder 26 to the line 28'or to exhaust line 36. The line 28 is preferably provided with a gauge 39 and a conventional pressure reducing valve 40. Preferably the pressure area of the piston I 8 in the cylinder I1 is from about one-fifth to one-sixth of the pressure area of the piston 24. Therefore, when low pressures are desired, only the device I5 is actuated, and the reducer valve 40 is adjusted to maintain a predetermined pressure Value in the line 30, thereby maintaining pressure-within a range of from, for example, fifty to three hundred pounds pressure per square inch on the hydraulic fluid within the cylinder fluid within the cylinder l2. arrangement an adjustable within the cylinder l2 are provided within a ratio of thirty to One, and it will be understood by those skilled in theart that such a range would be unfeasible with any conventional reducer valve 40. Furthermore, the'above-described arrangement afiords a relatively simple means for adjusting the pressure within the cylinder I 2 without the necessity of resorting to complicated and expensive valve mechanisms. The cylinder I2 is automatically charged by a pump 42 operated by a motor 44. The discharge side of the pump 42 is connected toa line 46 having a conventional safety relief valve :48 adapted to discharge at a predetermined maximum pressure value through a relief line 49,110 a reservoir 5| connected by a line 53 to the suction side of the pump 42. The valve 48 is adapted to function as a safety relief valve to prevent the building up of dangerous pressures by the pump 42 in the event of improper functioning of the actuating system for the pump, as hereinafter described. I .1 In operation of the novel system, when the volume of fluid in the cylinder I2 is at or below apresquare inch on the By means of this developing pressure a'gains'tthe determined minimum value, a rod 52 carried by the ram It closes a normally open switch 54 thereby closing a circu't through a solenoid coil 56 of a normally open double relay 58. Thus the coil 56 is energized by a conventional voltage supply 60 having one terminal connected to ground as at 6| and the'other terminal connected to one end of the coil. The opposite end of the coil is connected to one contact of the switch 54, the other contact of which at 63 thereby closing a circuit through the coil 58 as the switch 54 is closed. 7

Energization oi the coil'58 closes the relay '58 thereby closing a holding circuit through the coil 56 and a normally closed'switch 62 and-anthrough the motor M which is by a conventional voltage Isupother circuit thereby actuated ply 64.

As the motor M is energized, the pump 42 charges the cylinder 121mm the arm 52 engages the switch 62 thereby opening the same and deenergizing the coil "58 whereup'on'the relay 58 is opened breaking the holdingcircu'it throughthe "coil and also breaking the circuit through the motor M to stop'the pump 42. Makeup supplied to the line zby-the cylinder H! which is recharged, as above described, when'the switch E i is again closed as'the volume of pressure fluid in the cylinder 12 reaches the predetermined minimum'value at which the arm 52 engages-the switch 54.

It will be understood by those skilled in the art that, if desired, the motor M and pump 42 may operate continuously and the above-mentioned electrical control circuits may 'be con- -nected, for-example to the valve 138 .for actuation of the latter to by-p'ass 'theputput of the :pump '42 upon opening of the switch .62 and to deliver *the output of the pump 12 to theTline "46 :upon closing of the switch 54.

It' is'to'be understood that -we do not :wishyto be limited by the exact embodimentiof thedevice shownwhich is merely by way'of'illustration-and not limitation as various andother forms of the device will, of course, be apparent to those skilled in the art-without departing ffrom the spirit of the invention orthe scope of the 'claims.

We claim:

1. Anhydraulic*systemior suppl-yinglhydraulic fliiid under a predetermined pressure Icomprising "an hydraulic cylinder, a ram ther'ein, means :for external end rof said ram comprising a pair of piston and cylinder devices arranged inse'rieswith the pistoniof 'one device engagcable with 'said ram, "and the piston of the other device engageable with the inst-mentioned piston, means 'ior selectively supplying compressed gas to one for both of said devices to actuate'the sameya upump having its discharge side connected to said hydraulic cylin- -'der for charging .the same, electrically actuated means responsive to 'the position of said ram :for automatically actuating said pumpvvhen the N01- ume of hydraulic fluid in said hydraulic cylinder reaches a predetermined minimum value, and means responsive to theposition oisaidramrfor automatically deenergizing said electrically :actuatedlmeans when the volume .of hydraulic .fluid in *said hydraulic cylinder reaches a predetermine'd maximum value.

,2. A: systemior. supplying hydraulic fluid under pressure comprising an hydraulic chamber adapted to contain a supply of said fiuid,-a ram in :ssaid'c'ham'ber adapted to maintain '-a [predetermined'pressure on said fluid, a pair of pneumatic is connected to ground as ,pressure cylinders arranged in series, a piston in one of said pneumatic cylinders operatively connected to said ram to apply pressure thereto, a piston in the other pneumatic cylinder operatively connected to the first-mentioned piston to apply ,pressure therethrough to said ram, a source of pneumatic :fiuidgmeans forselectively connecting said source'to one or both of said cylinders, means .for adjusting the pressure of the pneumatic fluid supplied by said source to a predetermined value, a source of hydraulic pressure fluid, means for automatically delivering hydraulic fluid from the flast mentionedrsource to said chamber when the :volume 0f fluid therein reaches a predetermined minimum value, and means for automatically terminating the delivery of hydraulic fluid from the last-mentioned source when the volume of dluid -insaid chamber reaches a predetermined maximum value.

3. :A system'forrsupplying pressure comprising an hydraulic chamber adapted to supply-said -fluid,:a ram insaid chamber adapted to maintain a predetermined pressure on the fluid therein, a pair of pneumatic cylinders arranged in series, a ;pist0n.in:0l'1e of said cylinders :operatively connected to said ram to :apply pressure thereto, .a piston in the other ,=pneumatic cylinder :operatively connected to .the first-mentioned piston to apply ,pressure there- -through tosaid ram, a-.source-of pneumatic fluid, means -for selectively connecting said source to oneor bothof said cylinders, means. for adjusting the pressure of the pneumatic fluid supplied by said source to.a predetermined -va1ue,l-means.responsi-ve to the position of said ram .ior automatically deliveringhydraulic pressure fluid .to said chamber whenthevolume .of .fluid therein-reaches aspredeterminediminimum value, and means responsiveto the ,position of saidmamfor automatically terminating .the delivery (if hydraulic fluid to said chamber .whenlthevolume df fluid therein reaches a predetermined maximum value.

4. Asystemior supplyinghydraulic fluid under comprising .an hydraulic chamber adapted vto supply said'fluid, a ram in said chamber :adapted to maintain v.a predeterminedpressure on the .fluid therein, .a pneumatic cylinder, a piston therein operatively connected .to said ram to apply pressurethereto,.arsourceofrpneumatic 'fiuicl con- -nected to .said cylinder, means for adjusting 'the pressureof the pneumatic fluid supplied'bysaid source to l a predetermined value, means for.autohydraulic fluid .under matically.deliveringlhydraulicTfluid'to said chamber when the volume of 'fiuid therein reaches a predetermined minimum value, and means for automatically terminating delivery of hydraulic fluid .to said chamber when the volume of fluid thereinreaches apredetermined maximum value.

5. .A system for supplyinghydraulic fluid under pressure comprising an hydraulic chamber a'dapted'to supply said fluid, aram in said chamber adapted toima'intain.a predetermined,pressure on ;said fluid, means ffor developing a, predetermined pressure against said ram comprising a pneumatic :devi'ce, LasQurce of, pneumatic fluid undena predetermined pressure operatively connected .to said .device, means 'for automatically recharging said chamber, comprising means responsiveto'the position of saidmam for automatically delivering hydraulicfluidltorsaidchamber when the volume of fluid therein .reaches a predetermined .minimum valuegand means responsive to ,the position of said ram .for automatically terminating Ide- 175 liveryo'f fluid to said chamber when the volume of fluid therein reaches mum value.

6. An hydraulic system for supplying hydraulic fluid under a predetermined pressure value comprising an hydraulic cylinder, a ram therein, means for developing pressure against the external end of said ram comprising a plurality of piston and cylinder devices arranged in series with the respective pistons engageable with each other, means for selectively supplying compressed gas to one or a plurality of said devices to actuate the same against said ram, a source of hydraulic fluid under pressure greater than that exerted against said ram during actuation of all of said devices, said source being connected to said cylinder through one-way valve means accommodating flow of fluid to said cylinder, means for terminating flow of fluid from said source when the ram has been urged to its retracted position against the resistance of the first-mentioned means, and a supply line connected to said cylinder at the downstream side of said valve means for supplying fluid under pressure from said cylinder.

7. A system fOr supplying hydraulic fluid under pressure comprising an hydraulic cylinder, a rain therein, another cylinder containing a body of compressed gas, a piston in said other cylinder a predetermined maxion said ram b said piston, said source being connected to said hydraulic cylinder through one-Way valve means accommodating flow of fluid to said hydraulic cylinder, and a line connected to said hydraulic cylinder for supplyin hydraulic fluid therefrom.

8. A system, according to claim '7, wherein flow of fluid from said source to said hydraulic cylinder when the volume of fluid therein reaches a predetermined minimum value.

9. An hydraulic system for supplying hydraulic fluid under a predetermined pressure value comprising an hydraulic cylinder, a, ram therein, a

10. A system, according to claim 9, wherein condition responsive means are provided for supplying pressure fluid to said hydraulic cylinder when the volume of fluid therein reaches a prefluid therefrom.

1 A system, according to claim 11, wherein means are provided for automatically recharging said cylinder when the volume of fluid therein reaches a predetermined minimum value, and means are provided for rendering the first-mentioned means ineffective when the volume of fluid in said hydraulic cylinder reaches a predetermined maximum value.

13. A system for supplying hydraulic fluid un- EARL CANNON. EDWARD J. LUKES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,976,129 Johnson Oct. 9, 1934 1,979,407 Pike Nov. 6, 1934 2,313,404 Vickers Mar. 9, 1943 

